1. Field
Embodiments relate to a light emitting device including a light emitting module and a driving module.
2. Background
A light emitting diode (LED) may be widely used as a light emitting module. Use of an organic light emitting diode (OLED) is also increasing because the OLED has excellent color reproduction and a fast driving speed as compared to the LED. Applications of such a light emitting module may be expansive. For example, the light emitting module may be used as a high-luminance light source for a flash, a back light for a liquid crystal display (LCD) used in a portable electronic product such as, e.g., a mobile phone, a camcorder, a digital camera, a personal digital assistant (PDA), a light source for an electronic display, a light source for illumination and switch illumination, and/or a light source for a pilot lamp and traffic light. A light emitting module may receive driving power supplied by a driving module and may generate light by using the received driving power. Such a light emitting module may be referred to as an LED array module (LAM), and the driving module may be referred to as an LED drive module (LDM).
Referring to FIG. 1, a light emitting device 10 according to related art may include a plurality of driving modules and a plurality of light emitting modules. The plurality of light emitting modules may include a first light emitting module 20, a second light emitting module 30, and an Nth light emitting module 40. The plurality of driving modules may supply an operating voltage to the plurality of light emitting modules. The plurality of driving modules may include a first driving module 50 that supplies the operating voltage to the first light emitting module 20, a second driving module 60 that supplies the operating voltage to the second light emitting module 30, and an Nth driving module 70 that supplies the operating voltage to the Nth light emitting module 40. The first to Nth light emitting modules 20, 30, and 40 may be installed at different positions of a vehicle. For example, the first to Nth light emitting modules 20, 30, and 40 may include a front lamp including a day running light (DRL), a position lamp (PSTN), and/or a turn signal lamp (TSL), and a rear combination lamp including a stop lamp, a tail lamp, a turn signal lamp, a backup lamp, and/or a fog lamp.
Referring to FIG. 2, each of the plurality of driving modules may include a power input 81 that receives power, a constant voltage circuit 82 that converts the power received through the power input 81, and a constant current circuit 83 that supplies the power converted by the constant voltage circuit 82 to a that corresponds light emitting module. The constant voltage circuit 82 may not be configured to cover all of the first to Nth light emitting modules 20, 30, and 40, but may output a voltage suitable for an operating voltage of a specific light emitting module controlled by the constant voltage circuit 82. Similar to the constant voltage circuit 82, the constant current circuit 83 may output a constant current control suitable for an operating current of a specific light emitting module controlled by the constant current circuit 83. The plurality of driving modules may be designed for specific light emitting modules controlled by the driving modules and individually configured according to the number of light emitting modules.
However, if the light emitting device 10 is configured as described above, the number of driving modules may be increased to as many as a number of light emitting modules. This increase of the driving modules may increase unit costs and increase loss of product development.